<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
	</body>
	<script>
		test();
		function test() {
			var a = 8;
			// 左查询 对等号左侧的变量进行查询
			b = a;
			console.log(b);
		}
		// 右查询 等号的非左侧
		console.log(b);
	</script>
</html>
